Red Blood Cell Storage Lesion-Induced Adverse Effects: More Smoke; Is There Fire?
“Red Cell Transfusion-Associated Hemolysis in Cardiac Surgery: An Observational Cohort Study,” by Karkouti et al1 in this issue is a timely contribution to a growing body of literature on an important, but controversial, topic. That is, do red blood cell (RBC) transfusions per se, and transfusions of longer-stored RBC units, in particular, lead to adverse outcomes? The adverse outcomes under consideration are not the usual, better-understood ones, such as those due to transfusion-transmitted infectious diseases (eg, hepatitis C, human immunodeficiency virus), hemolytic or nonhemolytic transfusion reactions, transfusion-associated acute lung injury, or transfusion-associated circulatory overload. Rather this literature addresses whether there are additional, novel, adverse effects resulting simply from transfusions of refrigerator-stored RBCs themselves. Indeed, one could argue that the origin of all these types of studies began in 1999 with the surprising results in the TRICC trial,2 which showed that critically ill patients had better outcomes, including less mortality, when placed on a restrictive transfusion regimen, rather than a liberal one (ie, were transfused at a lower hemoglobin threshold, rather than a higher one). These results suggested that there was something “bad” about transfusing “too many” stored RBCs.